package org.owasp.esapi.codecs;

import org.owasp.esapi.ESAPI;
import org.owasp.esapi.Logger;

// CHECKME: Version at http://iharder.net/base64 is up to v2.3.3. Some semantic changes
// starting with v2.3. Should we upgrade and then add ESAPI logging or stay at 2.2.2 base?
// I think that really depends on how much OWASP ESAPI plans on tracking changes to this
// version vs. if the plan was just to fork from it and maintain OWASP's own version.
// At this point, I think I prefer split from tracking Harder's original, but I'm easily
// persuaded otherwise. (In fact, we have already done so w/ decodeToObject().) - Kevin Wall

/**
 * <p>Encodes and decodes to and from Base64 notation.</p>
 * <p>Homepage: <a href="http://iharder.net/base64">http://iharder.net/base64</a>
 * (based on version 2.2.2).</p>
 *
 * <p>The <tt>options</tt> parameter, which appears in a few places, is used to pass
 * several pieces of information to the encoder. In the "higher level" methods such as
 * encodeBytes( bytes, options ) the options parameter can be used to indicate such
 * things as first gzipping the bytes before encoding them, not inserting linefeeds
 * (though that breaks strict Base64 compatibility), and encoding using the URL-safe
 * and Ordered dialects.</p>
 *
 * <p>The constants defined in Base64 can be OR-ed together to combine options, so you
 * might make a call like this:</p>
 *
 * <code>String encoded = Base64.encodeBytes( mybytes, Base64.GZIP | Base64.DONT_BREAK_LINES );</code>
 *
 * <p>to compress the data before encoding it and then making the output have no newline characters.</p>
 *
 *
 * <p>
 * Original change Log:
 * </p>
 * <ul>
 *  <li>v2.2.2 - Fixed encodeFileToFile and decodeFileToFile to use the
 *   Base64.InputStream class to encode and decode on the fly which uses
 *   less memory than encoding/decoding an entire file into memory before writing.</li>
 *  <li>v2.2.1 - Fixed bug using URL_SAFE and ORDERED encodings. Fixed bug
 *   when using very small files (~< 40 bytes).</li>
 *  <li>v2.2 - Added some helper methods for encoding/decoding directly from
 *   one file to the next. Also added a main() method to support command line
 *   encoding/decoding from one file to the next. Also added these Base64 dialects:
 *   <ol>
 *   <li>The default is RFC3548 format.</li>
 *   <li>Calling Base64.setFormat(Base64.BASE64_FORMAT.URLSAFE_FORMAT) generates
 *   URL and file name friendly format as described in Section 4 of RFC3548.
 *   http://www.faqs.org/rfcs/rfc3548.html</li>
 *   <li>Calling Base64.setFormat(Base64.BASE64_FORMAT.ORDERED_FORMAT) generates
 *   URL and file name friendly format that preserves lexical ordering as described
 *   in http://www.faqs.org/qa/rfcc-1940.html</li>
 *   </ol>
 *   Special thanks to Jim Kellerman at <a href="http://www.powerset.com/">http://www.powerset.com/</a>
 *   for contributing the new Base64 dialects.
 *  </li>
 *
 *  <li>v2.1 - Cleaned up javadoc comments and unused variables and methods. Added
 *   some convenience methods for reading and writing to and from files.</li>
 *  <li>v2.0.2 - Now specifies UTF-8 encoding in places where the code fails on systems
 *   with other encodings (like EBCDIC).</li>
 *  <li>v2.0.1 - Fixed an error when decoding a single byte, that is, when the
 *   encoded data was a single byte.</li>
 *  <li>v2.0 - I got rid of methods that used booleans to set options.
 *   Now everything is more consolidated and cleaner. The code now detects
 *   when data that's being decoded is gzip-compressed and will decompress it
 *   automatically. Generally things are cleaner. You'll probably have to
 *   change some method calls that you were making to support the new
 *   options format (<tt>int</tt>s that you "OR" together).</li>
 *  <li>v1.5.1 - Fixed bug when decompressing and decoding to a
 *   byte[] using <tt>decode( String s, boolean gzipCompressed )</tt>.
 *   Added the ability to "suspend" encoding in the Output Stream so
 *   you can turn on and off the encoding if you need to embed base64
 *   data in an otherwise "normal" stream (like an XML file).</li>
 *  <li>v1.5 - Output stream passes on flush() command but doesn't do anything itself.
 *      This helps when using GZIP streams.
 *      Added the ability to GZip-compress objects before encoding them.</li>
 *  <li>v1.4 - Added helper methods to read/write files.</li>
 *  <li>v1.3.6 - Fixed OutputStream.flush() so that 'position' is reset.</li>
 *  <li>v1.3.5 - Added flag to turn on and off line breaks. Fixed bug in input stream
 *      where last buffer being read, if not completely full, was not returned.</li>
 *  <li>v1.3.4 - Fixed when "improperly padded stream" error was thrown at the wrong time.</li>
 *  <li>v1.3.3 - Fixed I/O streams which were totally messed up.</li>
 * </ul>
 *
 * <p>
 * I am placing this code in the Public Domain. Do with it as you will.
 * This software comes with no guarantees or warranties but with
 * plenty of well-wishing instead!
 * Please visit <a href="http://iharder.net/base64">http://iharder.net/base64</a>
 * periodically to check for updates or to contribute improvements.
 * </p>
 *
 * @author Robert Harder
 * @author rob@iharder.net
 * @version 2.2.2
 */
public class Base64
{

/* ********  P U B L I C   F I E L D S  ******** */


    /** No options specified. Value is zero. */
    public final static int NO_OPTIONS = 0;

    /** Specify encoding. */
    public final static int ENCODE = 1;

    /** Specify decoding. */
    public final static int DECODE = 0;

    /** Specify that data should be gzip-compressed. */
    public final static int GZIP = 2;

    /** Don't break lines when encoding (violates strict Base64 specification) */
    public final static int DONT_BREAK_LINES = 8;

    /**
     * Encode using Base64-like encoding that is URL- and Filename-safe as described
     * in Section 4 of RFC3548:
     * <a href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>.
     * It is important to note that data encoded this way is <em>not</em> officially valid Base64,
     * or at the very least should not be called Base64 without also specifying that is
     * was encoded using the URL- and Filename-safe dialect.
     */
     public final static int URL_SAFE = 16;

     /**
      * Encode using the special "ordered" dialect of Base64 described here:
      * <a href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
      */
     public final static int ORDERED = 32;

     /**
      * System property name that must be set to true in order to invoke {@code Base64.decodeToObject()}.
      * @link https://github.com/ESAPI/esapi-java-legacy/issues/354
      * @link http://foxglovesecurity.com/2015/11/06/what-do-weblogic-websphere-jboss-jenkins-opennms-and-your-application-have-in-common-this-vulnerability/
      */
     public final static String ENABLE_UNSAFE_SERIALIZATION = "org.owasp.esapi.enableUnsafeSerialization"; // Do NOT change!

/* ********  P R I V A T E   F I E L D S  ******** */

    /** Maximum line length (76) of Base64 output. */
    private final static int MAX_LINE_LENGTH = 76;

    /** The equals sign (=) as a byte. */
    private final static byte EQUALS_SIGN = (byte)'=';

    /** The new line character (\n) as a byte. */
    private final static byte NEW_LINE = (byte)'\n';

    /** Preferred encoding. */
    private final static String PREFERRED_ENCODING = "UTF-8";

    /** End of line character. */
    private final static String EOL = System.getProperty("line.separator", "\n");


    // I think I end up not using the BAD_ENCODING indicator.
    //private final static byte BAD_ENCODING    = -9; // Indicates error in encoding
    private final static byte WHITE_SPACE_ENC = -5; // Indicates white space in encoding
    private final static byte EQUALS_SIGN_ENC = -1; // Indicates equals sign in encoding

    private static final Logger logger = ESAPI.getLogger("Base64");

/* ********  S T A N D A R D   B A S E 6 4   A L P H A B E T  ******** */

    /** The 64 valid Base64 values. */
    //private final static byte[] ALPHABET;
    /* Host platform me be something funny like EBCDIC, so we hard code these values. */
    private final static byte[] _STANDARD_ALPHABET =
    {
        (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
        (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
        (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
        (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
        (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
        (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
        (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
        (byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z',
        (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5',
        (byte)'6', (byte)'7', (byte)'8', (byte)'9', (byte)'+', (byte)'/'
    };

    /**
     * Translates a Base64 value to either its 6-bit reconstruction value
     * or a negative number indicating some other meaning.
     **/
    private final static byte[] _STANDARD_DECODABET =
    {
        -9,-9,-9,-9,-9,-9,-9,-9,-9,                 // Decimal  0 -  8
        -5,-5,                                      // Whitespace: Tab and Linefeed
        -9,-9,                                      // Decimal 11 - 12
        -5,                                         // Whitespace: Carriage Return
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 14 - 26
        -9,-9,-9,-9,-9,                             // Decimal 27 - 31
        -5,                                         // Whitespace: Space
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,              // Decimal 33 - 42
        62,                                         // Plus sign at decimal 43
        -9,-9,-9,                                   // Decimal 44 - 46
        63,                                         // Slash at decimal 47
        52,53,54,55,56,57,58,59,60,61,              // Numbers zero through nine
        -9,-9,-9,                                   // Decimal 58 - 60
        -1,                                         // Equals sign at decimal 61
        -9,-9,-9,                                      // Decimal 62 - 64
        0,1,2,3,4,5,6,7,8,9,10,11,12,13,            // Letters 'A' through 'N'
        14,15,16,17,18,19,20,21,22,23,24,25,        // Letters 'O' through 'Z'
        -9,-9,-9,-9,-9,-9,                          // Decimal 91 - 96
        26,27,28,29,30,31,32,33,34,35,36,37,38,     // Letters 'a' through 'm'
        39,40,41,42,43,44,45,46,47,48,49,50,51,     // Letters 'n' through 'z'
        -9,-9,-9,-9                                 // Decimal 123 - 126
        /*,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 127 - 139
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 140 - 152
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 153 - 165
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 166 - 178
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 179 - 191
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 192 - 204
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 205 - 217
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 218 - 230
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 231 - 243
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9         // Decimal 244 - 255 */
    };


/* ********  U R L   S A F E   B A S E 6 4   A L P H A B E T  ******** */

    /**
     * Used in the URL- and Filename-safe dialect described in Section 4 of RFC3548:
     * <a href="http://www.faqs.org/rfcs/rfc3548.html">http://www.faqs.org/rfcs/rfc3548.html</a>.
     * Notice that the last two bytes become "hyphen" and "underscore" instead of "plus" and "slash."
     */
    private final static byte[] _URL_SAFE_ALPHABET =
    {
      (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
      (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
      (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
      (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
      (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
      (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
      (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
      (byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z',
      (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4', (byte)'5',
      (byte)'6', (byte)'7', (byte)'8', (byte)'9', (byte)'-', (byte)'_'
    };

    /**
     * Used in decoding URL- and Filename-safe dialects of Base64.
     */
    private final static byte[] _URL_SAFE_DECODABET =
    {
      -9,-9,-9,-9,-9,-9,-9,-9,-9,                 // Decimal  0 -  8
      -5,-5,                                      // Whitespace: Tab and Linefeed
      -9,-9,                                      // Decimal 11 - 12
      -5,                                         // Whitespace: Carriage Return
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 14 - 26
      -9,-9,-9,-9,-9,                             // Decimal 27 - 31
      -5,                                         // Whitespace: Space
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,              // Decimal 33 - 42
      -9,                                         // Plus sign at decimal 43
      -9,                                         // Decimal 44
      62,                                         // Minus sign at decimal 45
      -9,                                         // Decimal 46
      -9,                                         // Slash at decimal 47
      52,53,54,55,56,57,58,59,60,61,              // Numbers zero through nine
      -9,-9,-9,                                   // Decimal 58 - 60
      -1,                                         // Equals sign at decimal 61
      -9,-9,-9,                                   // Decimal 62 - 64
      0,1,2,3,4,5,6,7,8,9,10,11,12,13,            // Letters 'A' through 'N'
      14,15,16,17,18,19,20,21,22,23,24,25,        // Letters 'O' through 'Z'
      -9,-9,-9,-9,                                // Decimal 91 - 94
      63,                                         // Underscore at decimal 95
      -9,                                         // Decimal 96
      26,27,28,29,30,31,32,33,34,35,36,37,38,     // Letters 'a' through 'm'
      39,40,41,42,43,44,45,46,47,48,49,50,51,     // Letters 'n' through 'z'
      -9,-9,-9,-9                                 // Decimal 123 - 126
      /*,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 127 - 139
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 140 - 152
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 153 - 165
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 166 - 178
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 179 - 191
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 192 - 204
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 205 - 217
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 218 - 230
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 231 - 243
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9         // Decimal 244 - 255 */
    };



/* ********  O R D E R E D   B A S E 6 4   A L P H A B E T  ******** */

    /**
     * I don't get the point of this technique, but it is described here:
     * <a href="http://www.faqs.org/qa/rfcc-1940.html">http://www.faqs.org/qa/rfcc-1940.html</a>.
     */
    private final static byte[] _ORDERED_ALPHABET =
    {
      (byte)'-',
      (byte)'0', (byte)'1', (byte)'2', (byte)'3', (byte)'4',
      (byte)'5', (byte)'6', (byte)'7', (byte)'8', (byte)'9',
      (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
      (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
      (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
      (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
      (byte)'_',
      (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
      (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
      (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
      (byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z'
    };

    /**
     * Used in decoding the "ordered" dialect of Base64.
     */
    private final static byte[] _ORDERED_DECODABET =
    {
      -9,-9,-9,-9,-9,-9,-9,-9,-9,                 // Decimal  0 -  8
      -5,-5,                                      // Whitespace: Tab and Linefeed
      -9,-9,                                      // Decimal 11 - 12
      -5,                                         // Whitespace: Carriage Return
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 14 - 26
      -9,-9,-9,-9,-9,                             // Decimal 27 - 31
      -5,                                         // Whitespace: Space
      -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,              // Decimal 33 - 42
      -9,                                         // Plus sign at decimal 43
      -9,                                         // Decimal 44
      0,                                          // Minus sign at decimal 45
      -9,                                         // Decimal 46
      -9,                                         // Slash at decimal 47
      1,2,3,4,5,6,7,8,9,10,                       // Numbers zero through nine
      -9,-9,-9,                                   // Decimal 58 - 60
      -1,                                         // Equals sign at decimal 61
      -9,-9,-9,                                   // Decimal 62 - 64
      11,12,13,14,15,16,17,18,19,20,21,22,23,     // Letters 'A' through 'M'
      24,25,26,27,28,29,30,31,32,33,34,35,36,     // Letters 'N' through 'Z'
      -9,-9,-9,-9,                                // Decimal 91 - 94
      37,                                         // Underscore at decimal 95
      -9,                                         // Decimal 96
      38,39,40,41,42,43,44,45,46,47,48,49,50,     // Letters 'a' through 'm'
      51,52,53,54,55,56,57,58,59,60,61,62,63,     // Letters 'n' through 'z'
      -9,-9,-9,-9                                 // Decimal 123 - 126
      /*,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 127 - 139
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 140 - 152
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 153 - 165
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 166 - 178
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 179 - 191
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 192 - 204
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 205 - 217
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 218 - 230
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,     // Decimal 231 - 243
        -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9         // Decimal 244 - 255 */
    };


/* ********  D E T E R M I N E   W H I C H   A L H A B E T  ******** */


    /**
     * Returns one of the _SOMETHING_ALPHABET byte arrays depending on
     * the options specified.
     * It's possible, though silly, to specify ORDERED and URLSAFE
     * in which case one of them will be picked, though there is
     * no guarantee as to which one will be picked.
     */
    private final static byte[] getAlphabet( int options )
    {
        if( (options & URL_SAFE) == URL_SAFE ) return _URL_SAFE_ALPHABET;
        else if( (options & ORDERED) == ORDERED ) return _ORDERED_ALPHABET;
        else return _STANDARD_ALPHABET;

    }   // end getAlphabet


    /**
     * Returns one of the _SOMETHING_DECODABET byte arrays depending on
     * the options specified.
     * It's possible, though silly, to specify ORDERED and URL_SAFE
     * in which case one of them will be picked, though there is
     * no guarantee as to which one will be picked.
     */
    private final static byte[] getDecodabet( int options )
    {
        if( (options & URL_SAFE) == URL_SAFE ) return _URL_SAFE_DECODABET;
        else if( (options & ORDERED) == ORDERED ) return _ORDERED_DECODABET;
        else return _STANDARD_DECODABET;

    }   // end getDecodaabet

    /** Defeats instantiation. */
    private Base64(){}

    /**
     * Encodes or decodes two files from the command line;
     * <strong>feel free to delete this method (in fact you probably should)
     * if you're embedding this code into a larger program</strong>.
     * @param args
     */
    public final static void main( String[] args )
    {
        if( args.length < 3 ){
            usage("Not enough arguments.");
        }   // end if: args.length < 3
        else {
            String flag = args[0];
            String infile = args[1];
            String outfile = args[2];
            if( flag.equals( "-e" ) ){
                Base64.encodeFileToFile( infile, outfile );
            }   // end if: encode
            else if( flag.equals( "-d" ) ) {
                Base64.decodeFileToFile( infile, outfile );
            }   // end else if: decode
            else {
                usage( "Unknown flag: " + flag );
            }   // end else
        }   // end else
    }   // end main

    /**
     * Prints command line usage.
     *
     * @param msg A message to include with usage info.
     */
    private final static void usage( String msg )
    {
        System.err.println( msg );
        System.err.println( "Usage: java Base64 -e|-d inputfile outputfile" );
    }   // end usage

/* ********  E N C O D I N G   M E T H O D S  ******** */

    /**
     * Encodes up to the first three bytes of array <var>threeBytes</var>
     * and returns a four-byte array in Base64 notation.
     * The actual number of significant bytes in your array is
     * given by <var>numSigBytes</var>.
     * The array <var>threeBytes</var> needs only be as big as
     * <var>numSigBytes</var>.
     * Code can reuse a byte array by passing a four-byte array as <var>b4</var>.
     *
     * @param b4 A reusable byte array to reduce array instantiation
     * @param threeBytes the array to convert
     * @param numSigBytes the number of significant bytes in your array
     * @return four byte array in Base64 notation.
     * @since 1.5.1
     */
    private static byte[] encode3to4( byte[] b4, byte[] threeBytes, int numSigBytes, int options )
    {
        encode3to4( threeBytes, 0, numSigBytes, b4, 0, options );
        return b4;
    }   // end encode3to4

    /**
     * <p>Encodes up to three bytes of the array <var>source</var>
     * and writes the resulting four Base64 bytes to <var>destination</var>.
     * The source and destination arrays can be manipulated
     * anywhere along their length by specifying
     * <var>srcOffset</var> and <var>destOffset</var>.
     * This method does not check to make sure your arrays
     * are large enough to accomodate <var>srcOffset</var> + 3 for
     * the <var>source</var> array or <var>destOffset</var> + 4 for
     * the <var>destination</var> array.
     * The actual number of significant bytes in your array is
     * given by <var>numSigBytes</var>.</p>
     * <p>This is the lowest level of the encoding methods with
     * all possible parameters.</p>
     *
     * @param source the array to convert
     * @param srcOffset the index where conversion begins
     * @param numSigBytes the number of significant bytes in your array
     * @param destination the array to hold the conversion
     * @param destOffset the index where output will be put
     * @return the <var>destination</var> array
     * @since 1.3
     */
    private static byte[] encode3to4(
        byte[] source, int srcOffset, int numSigBytes,
        byte[] destination, int destOffset, int options )
    {
        byte[] ALPHABET = getAlphabet( options );

        //           1         2         3
        // 01234567890123456789012345678901 Bit position
        // --------000000001111111122222222 Array position from threeBytes
        // --------|    ||    ||    ||    | Six bit groups to index ALPHABET
        //          >>18  >>12  >> 6  >> 0  Right shift necessary
        //                0x3f  0x3f  0x3f  Additional AND

        // Create buffer with zero-padding if there are only one or two
        // significant bytes passed in the array.
        // We have to shift left 24 in order to flush out the 1's that appear
        // when Java treats a value as negative that is cast from a byte to an int.
        int inBuff =   ( numSigBytes > 0 ? ((source[ srcOffset     ] << 24) >>>  8) : 0 )
                     | ( numSigBytes > 1 ? ((source[ srcOffset + 1 ] << 24) >>> 16) : 0 )
                     | ( numSigBytes > 2 ? ((source[ srcOffset + 2 ] << 24) >>> 24) : 0 );

        switch( numSigBytes )
        {
            case 3:
                destination[ destOffset     ] = ALPHABET[ (inBuff >>> 18)        ];
                destination[ destOffset + 1 ] = ALPHABET[ (inBuff >>> 12) & 0x3f ];
                destination[ destOffset + 2 ] = ALPHABET[ (inBuff >>>  6) & 0x3f ];
                destination[ destOffset + 3 ] = ALPHABET[ (inBuff       ) & 0x3f ];
                return destination;

            case 2:
                destination[ destOffset     ] = ALPHABET[ (inBuff >>> 18)        ];
                destination[ destOffset + 1 ] = ALPHABET[ (inBuff >>> 12) & 0x3f ];
                destination[ destOffset + 2 ] = ALPHABET[ (inBuff >>>  6) & 0x3f ];
                destination[ destOffset + 3 ] = EQUALS_SIGN;
                return destination;

            case 1:
                destination[ destOffset     ] = ALPHABET[ (inBuff >>> 18)        ];
                destination[ destOffset + 1 ] = ALPHABET[ (inBuff >>> 12) & 0x3f ];
                destination[ destOffset + 2 ] = EQUALS_SIGN;
                destination[ destOffset + 3 ] = EQUALS_SIGN;
                return destination;

            default:
                return destination;
        }   // end switch
    }   // end encode3to4

    /**
     * Encodes a byte array into Base64 notation.
     * Does not GZip-compress data.
     *
     * @param source The data to convert
     * @return The Base64-encoded resulting string
     * @since 1.4
     */
    public static String encodeBytes( byte[] source )
    {
        return encodeBytes( source, 0, source.length, NO_OPTIONS );
    }   // end encodeBytes



    /**
     * Encodes a byte array into Base64 notation.
     * <p>
     * Valid options:<pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DONT_BREAK_LINES: don't break lines at 76 characters
     *     <i>Note: Technically, this makes your encoding non-compliant.</i>
     * </pre>
     * <p>
     * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
     * <p>
     * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
     *
     *
     * @param source The data to convert
     * @param options Specified options
     * @return The Base64-encoded resulting string
     * @see Base64#GZIP
     * @see Base64#DONT_BREAK_LINES
     * @since 2.0
     */
    public static String encodeBytes( byte[] source, int options )
    {
        return encodeBytes( source, 0, source.length, options );
    }   // end encodeBytes

    /**
     * Encodes a byte array into Base64 notation.
     * Does not GZip-compress data.
     *
     * @param source The data to convert
     * @param off Offset in array where conversion should begin
     * @param len Length of data to convert
     * @return The Base64-encoded resulting string
     * @since 1.4
     */
    public static String encodeBytes( byte[] source, int off, int len )
    {
        return encodeBytes( source, off, len, NO_OPTIONS );
    }   // end encodeBytes

    /**
     * Encodes a byte array into Base64 notation.
     * <p>
     * Valid options:<pre>
     *   GZIP: gzip-compresses object before encoding it.
     *   DONT_BREAK_LINES: don't break lines at 76 characters
     *     <i>Note: Technically, this makes your encoding non-compliant.</i>
     * </pre>
     * <p>
     * Example: <code>encodeBytes( myData, Base64.GZIP )</code> or
     * <p>
     * Example: <code>encodeBytes( myData, Base64.GZIP | Base64.DONT_BREAK_LINES )</code>
     *
     *
     * @param source The data to convert
     * @param off Offset in array where conversion should begin
     * @param len Length of data to convert
     * @param options alphabet type is pulled from this (standard, url-safe, ordered)
     * @return The Base64-encoded resulting string
     * @see Base64#GZIP
     * @see Base64#DONT_BREAK_LINES
     * @since 2.0
     */
    public static String encodeBytes( byte[] source, int off, int len, int options )
    {
        // Isolate options
        int dontBreakLines = ( options & DONT_BREAK_LINES );
        int gzip           = ( options & GZIP   );

        // Compress?
        if( gzip == GZIP )
        {
            java.io.ByteArrayOutputStream  baos  = null;
            java.util.zip.GZIPOutputStream gzos  = null;
            Base64.OutputStream            b64os = null;

            try
            {
                // GZip -> Base64 -> ByteArray
                baos = new java.io.ByteArrayOutputStream();
                b64os = new Base64.OutputStream( baos, ENCODE | options );
                gzos  = new java.util.zip.GZIPOutputStream( b64os );

                gzos.write( source, off, len );
                gzos.close();
            }   // end try
            catch( java.io.IOException e )
            {
                logger.error( Logger.SECURITY_FAILURE, "Problem writing gzip stream", e );
                return null;
            }   // end catch
            finally
            {
                try{ gzos.close();  } catch( Exception e ){}
                try{ b64os.close(); } catch( Exception e ){}
                try{ baos.close();  } catch( Exception e ){}
            }   // end finally

            // Return value according to relevant encoding.
            try
            {
                return new String( baos.toByteArray(), PREFERRED_ENCODING );
            }   // end try
            catch (java.io.UnsupportedEncodingException uue)
            {
                return new String( baos.toByteArray() );
            }   // end catch
        }   // end if: compress

        // Else, don't compress. Better not to use streams at all then.
        else
        {
            // Convert option to boolean in way that code likes it.
            boolean breakLines = dontBreakLines == 0;

            int    len43   = len * 4 / 3;
            byte[] outBuff = new byte[   ( len43 )                      // Main 4:3
                                       + ( (len % 3) > 0 ? 4 : 0 )      // Account for padding
                                       + (breakLines ? ( len43 / MAX_LINE_LENGTH ) : 0) ]; // New lines
            int d = 0;
            int e = 0;
            int len2 = len - 2;
            int lineLength = 0;
            for( ; d < len2; d+=3, e+=4 )
            {
                encode3to4( source, d+off, 3, outBuff, e, options );

                lineLength += 4;
                if( breakLines && lineLength == MAX_LINE_LENGTH )
                {
                    outBuff[e+4] = NEW_LINE;
                    e++;
                    lineLength = 0;
                }   // end if: end of line
            }   // en dfor: each piece of array

            if( d < len )
            {
                encode3to4( source, d+off, len - d, outBuff, e, options );
                e += 4;
            }   // end if: some padding needed


            // Return value according to relevant encoding.
            try
            {
                return new String( outBuff, 0, e, PREFERRED_ENCODING );
            }   // end try
            catch (java.io.UnsupportedEncodingException uue)
            {
                return new String( outBuff, 0, e );
            }   // end catch

        }   // end else: don't compress

    }   // end encodeBytes

/* ********  D E C O D I N G   M E T H O D S  ******** */

    /**
     * Decodes four bytes from array <var>source</var>
     * and writes the resulting bytes (up to three of them)
     * to <var>destination</var>.
     * The source and destination arrays can be manipulated
     * anywhere along their length by specifying
     * <var>srcOffset</var> and <var>destOffset</var>.
     * This method does not check to make sure your arrays
     * are large enough to accomodate <var>srcOffset</var> + 4 for
     * the <var>source</var> array or <var>destOffset</var> + 3 for
     * the <var>destination</var> array.
     * This method returns the actual number of bytes that
     * were converted from the Base64 encoding.
     * <p>This is the lowest level of the decoding methods with
     * all possible parameters.</p>
     *
     *
     * @param source the array to convert
     * @param srcOffset the index where conversion begins
     * @param destination the array to hold the conversion
     * @param destOffset the index where output will be put
     * @param options alphabet type is pulled from this (standard, url-safe, ordered)
     * @return the number of decoded bytes converted
     * @since 1.3
     */
    private static int decode4to3( byte[] source, int srcOffset, byte[] destination, int destOffset, int options )
    {
        byte[] DECODABET = getDecodabet( options );

        // Example: Dk==
        if( source[ srcOffset + 2] == EQUALS_SIGN )
        {
            // Two ways to do the same thing. Don't know which way I like best.
            //int outBuff =   ( ( DECODABET[ source[ srcOffset    ] ] << 24 ) >>>  6 )
            //              | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 );
            int outBuff =   ( ( DECODABET[ source[ srcOffset    ] ] & 0xFF ) << 18 )
                          | ( ( DECODABET[ source[ srcOffset + 1] ] & 0xFF ) << 12 );

            destination[ destOffset ] = (byte)( outBuff >>> 16 );
            return 1;
        }

        // Example: DkL=
        else if( source[ srcOffset + 3 ] == EQUALS_SIGN )
        {
            // Two ways to do the same thing. Don't know which way I like best.
            //int outBuff =   ( ( DECODABET[ source[ srcOffset     ] ] << 24 ) >>>  6 )
            //              | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
            //              | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 );
            int outBuff =   ( ( DECODABET[ source[ srcOffset     ] ] & 0xFF ) << 18 )
                          | ( ( DECODABET[ source[ srcOffset + 1 ] ] & 0xFF ) << 12 )
                          | ( ( DECODABET[ source[ srcOffset + 2 ] ] & 0xFF ) <<  6 );

            destination[ destOffset     ] = (byte)( outBuff >>> 16 );
            destination[ destOffset + 1 ] = (byte)( outBuff >>>  8 );
            return 2;
        }

        // Example: DkLE
        else
        {
            try{
            // Two ways to do the same thing. Don't know which way I like best.
            //int outBuff =   ( ( DECODABET[ source[ srcOffset     ] ] << 24 ) >>>  6 )
            //              | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
            //              | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 )
            //              | ( ( DECODABET[ source[ srcOffset + 3 ] ] << 24 ) >>> 24 );
            int outBuff =   ( ( DECODABET[ source[ srcOffset     ] ] & 0xFF ) << 18 )
                          | ( ( DECODABET[ source[ srcOffset + 1 ] ] & 0xFF ) << 12 )
                          | ( ( DECODABET[ source[ srcOffset + 2 ] ] & 0xFF ) <<  6)
                          | ( ( DECODABET[ source[ srcOffset + 3 ] ] & 0xFF )      );


            destination[ destOffset     ] = (byte)( outBuff >> 16 );
            destination[ destOffset + 1 ] = (byte)( outBuff >>  8 );
            destination[ destOffset + 2 ] = (byte)( outBuff       );

            return 3;
            }catch( Exception e){

        // Remove these after checking -- for context only.
                // logger.error( Logger.SECURITY_FAILURE, "Problem writing object", e );
                // logger.error( Logger.SECURITY_FAILURE, ""+source[srcOffset]+ ": " + ( DECODABET[ source[ srcOffset     ] ]  ) );
                // logger.error( Logger.SECURITY_FAILURE, ""+source[srcOffset+1]+  ": " + ( DECODABET[ source[ srcOffset + 1 ] ]  ) );
                // logger.error( Logger.SECURITY_FAILURE, ""+source[srcOffset+2]+  ": " + ( DECODABET[ source[ srcOffset + 2 ] ]  ) );
                // logger.error( Logger.SECURITY_FAILURE, ""+source[srcOffset+3]+  ": " + ( DECODABET[ source[ srcOffset + 3 ] ]  ) );

            // CHECKME: I replaced the 5 separate logger.error() calls above with a single logger.error() call so they can't
            // become interleaved with other log entries from other threads. Normally this would have placed log entries
            // on separate lines, so I also added line terminators here as well. (Probably don't want it all on one single
            // really long log entry, do we?) Anyhow, somebody should check the formatting to ensure that it's
            // esthetically pleasing, etc. But this works for me. I'm also OK if you want to remove all the line terminators
            // in which case the declaration for EOL should be removed as well.     - Kevin Wall

                StringBuilder sb = new StringBuilder("Problem writing object:");
                sb.append(EOL);
                sb.append( source[srcOffset]   ).append(": ").append( ( DECODABET[ source[ srcOffset     ] ]  ) ).append(EOL);
                sb.append( source[srcOffset+1] ).append(": ").append( ( DECODABET[ source[ srcOffset + 1 ] ]  ) ).append(EOL);
                sb.append( source[srcOffset+2] ).append(": ").append( ( DECODABET[ source[ srcOffset + 2 ] ]  ) ).append(EOL);
                sb.append( source[srcOffset+3] ).append(": ").append( ( DECODABET[ source[ srcOffset + 3 ] ]  ) ).append(EOL);

                logger.error( Logger.SECURITY_FAILURE, sb.toString(), e );
                return -1;
            }   // end catch
        }
    }   // end decodeToBytes

    /**
     * Very low-level access to decoding ASCII characters in
     * the form of a byte array. Does not support automatically
     * gunzipping or any other "fancy" features.
     *
     * @param source The Base64 encoded data
     * @param off    The offset of where to begin decoding
     * @param len    The length of characters to decode
     * @param options
     * @return decoded data
     * @since 1.3
     */
    public static byte[] decode( byte[] source, int off, int len, int options )
    {
        byte[] DECODABET = getDecodabet( options );

        int    len34   = len * 3 / 4;
        byte[] outBuff = new byte[ len34 ]; // Upper limit on size of output
        int    outBuffPosn = 0;

        byte[] b4        = new byte[4];
        int    b4Posn    = 0;
        int    i         = 0;
        byte   sbiCrop   = 0;
        byte   sbiDecode = 0;
        for( i = off; i < off+len; i++ )
        {
            sbiCrop = (byte)(source[i] & 0x7f); // Only the low seven bits
            sbiDecode = DECODABET[ sbiCrop ];

            if( sbiDecode >= WHITE_SPACE_ENC ) // White space, Equals sign or better
            {
                if( sbiDecode >= EQUALS_SIGN_ENC )
                {
                    b4[ b4Posn++ ] = sbiCrop;
                    if( b4Posn > 3 )
                    {
                        outBuffPosn += decode4to3( b4, 0, outBuff, outBuffPosn, options );
                        b4Posn = 0;

                        // If that was the equals sign, break out of 'for' loop
                        if( sbiCrop == EQUALS_SIGN )
                            break;
                    }   // end if: quartet built

                }   // end if: equals sign or better

            }   // end if: white space, equals sign or better
            else
            {
                logger.error( Logger.SECURITY_FAILURE, "Bad Base64 input character at " + i + ": " + source[i] + "(decimal)" );
                return null;
            }   // end else:
        }   // each input character

        byte[] out = new byte[ outBuffPosn ];
        System.arraycopy( outBuff, 0, out, 0, outBuffPosn );
        return out;
    }   // end decode

    /**
     * Decodes data from Base64 notation, automatically
     * detecting gzip-compressed data and decompressing it.
     *
     * @param s the string to decode
     * @return the decoded data
     * @since 1.4
     */
    public static byte[] decode( String s )
    {
        return decode( s, NO_OPTIONS );
    }

    /**
     * Decodes data from Base64 notation, automatically
     * detecting gzip-compressed data and decompressing it.
     *
     * @param s the string to decode
     * @param options encode options such as URL_SAFE
     * @return the decoded data
     * @since 1.4
     */
    public static byte[] decode( String s, int options )
    {
        byte[] bytes;
        try
        {
            bytes = s.getBytes( PREFERRED_ENCODING );
        }
        catch( java.io.UnsupportedEncodingException uee )
        {
            bytes = s.getBytes();   // Uses native encoding
            // CHECKME: Is this correct? I think it should be a warning instead of an error since nothing
            // is re-thrown. I do think that *some* sort of logging is in order here  especially since UTF-8 should
            // always be available on all platforms. If it's not, then all bets are off on your runtime env. - Kevin Wall
            logger.warning( Logger.SECURITY_FAILURE, "Problem decoding string using " +
                            PREFERRED_ENCODING + "; substituting native platform encoding instead", uee );
        }

        // Decode
        bytes = decode( bytes, 0, bytes.length, options );

        // Check to see if it's gzip-compressed
        // GZIP Magic Two-Byte Number: 0x8b1f (35615)
        if( bytes != null && bytes.length >= 4 )
        {

            int head = ((int)bytes[0] & 0xff) | ((bytes[1] << 8) & 0xff00);
            if ( java.util.zip.GZIPInputStream.GZIP_MAGIC == head )
            {
                java.io.ByteArrayInputStream  bais = null;
                java.util.zip.GZIPInputStream gzis = null;
                java.io.ByteArrayOutputStream baos = null;
                byte[] buffer = new byte[2048];
                int    length = 0;

                try
                {
                    baos = new java.io.ByteArrayOutputStream();
                    bais = new java.io.ByteArrayInputStream( bytes );
                    gzis = new java.util.zip.GZIPInputStream( bais );

                    while( ( length = gzis.read( buffer ) ) >= 0 )
                    {
                        baos.write(buffer,0,length);
                    }   // end while: reading input

                    // No error? Get new bytes.
                    bytes = baos.toByteArray();

                }   // end try
                catch( java.io.IOException e )
                {
                    // Just return originally-decoded bytes
                }   // end catch
                finally
                {
                    try{ baos.close(); } catch( Exception e ){}
                    try{ gzis.close(); } catch( Exception e ){}
                    try{ bais.close(); } catch( Exception e ){}
                }   // end finally

            }   // end if: gzipped
        }   // end if: bytes.length >= 2

        return bytes;
    }   // end decode

    /**
     * Convenience method for encoding data to a file.
     *
     * @param dataToEncode byte array of data to encode in base64 form
     * @param filename Filename for saving encoded data
     * @return <tt>true</tt> if successful, <tt>false</tt> otherwise
     *
     * @since 2.1
     */
    public static boolean encodeToFile( byte[] dataToEncode, String filename )
    {
        boolean success = false;
        Base64.OutputStream bos = null;
        try
        {
            bos = new Base64.OutputStream(
                      new java.io.FileOutputStream( filename ), Base64.ENCODE );
            bos.write( dataToEncode );
            success = true;
        }   // end try
        catch( java.io.IOException e )
        {

            success = false;
        }   // end catch: IOException
        finally
        {
            try{ bos.close(); } catch( Exception e ){}
        }   // end finally

        return success;
    }   // end encodeToFile

    /**
     * Convenience method for decoding data to a file.
     *
     * @param dataToDecode Base64-encoded data as a string
     * @param filename Filename for saving decoded data
     * @return <tt>true</tt> if successful, <tt>false</tt> otherwise
     *
     * @since 2.1
     */
    public static boolean decodeToFile( String dataToDecode, String filename )
    {
        boolean success = false;
        Base64.OutputStream bos = null;
        try
        {
                bos = new Base64.OutputStream(
                          new java.io.FileOutputStream( filename ), Base64.DECODE );
                bos.write( dataToDecode.getBytes( PREFERRED_ENCODING ) );
                success = true;
        }   // end try
        catch( java.io.IOException e )
        {
            success = false;
        }   // end catch: IOException
        finally
        {
                try{ bos.close(); } catch( Exception e ){}
        }   // end finally

        return success;
    }   // end decodeToFile

    /**
     * Convenience method for reading a base64-encoded
     * file and decoding it.
     *
     * @param filename Filename for reading encoded data
     * @return decoded byte array or null if unsuccessful
     *
     * @since 2.1
     */
    public static byte[] decodeFromFile( String filename )
    {
        byte[] decodedData = null;
        Base64.InputStream bis = null;
        try
        {
            // Set up some useful variables
            java.io.File file = new java.io.File( filename );
            byte[] buffer = null;
            int length   = 0;
            int numBytes = 0;

            // Check for size of file
            if( file.length() > Integer.MAX_VALUE )
            {
                logger.error( Logger.SECURITY_FAILURE, "File is too big for this convenience method (" + file.length() + " bytes)." );
                return null;
            }   // end if: file too big for int index
            buffer = new byte[ (int)file.length() ];

            // Open a stream
            bis = new Base64.InputStream(
                      new java.io.BufferedInputStream(
                      new java.io.FileInputStream( file ) ), Base64.DECODE );

            // Read until done
            while( ( numBytes = bis.read( buffer, length, 4096 ) ) >= 0 )
                length += numBytes;

            // Save in a variable to return
            decodedData = new byte[ length ];
            System.arraycopy( buffer, 0, decodedData, 0, length );

        }   // end try
        catch( java.io.IOException e )
        {
            logger.error( Logger.SECURITY_FAILURE, "Error decoding from file " + filename, e );
        }   // end catch: IOException
        finally
        {
            try{ if (bis != null ) bis.close(); } catch( Exception e) {}
        }   // end finally

        return decodedData;
    }   // end decodeFromFile

    /**
     * Convenience method for reading a binary file
     * and base64-encoding it.
     *
     * @param filename Filename for reading binary data
     * @return base64-encoded string or null if unsuccessful
     *
     * @since 2.1
     */
    public static String encodeFromFile( String filename )
    {
        String encodedData = null;
        Base64.InputStream bis = null;
        try
        {
            // Set up some useful variables
            java.io.File file = new java.io.File( filename );
            byte[] buffer = new byte[ Math.max((int)(file.length() * 1.4),40) ]; // Need max() for math on small files (v2.2.1)
            int length   = 0;
            int numBytes = 0;

            // Open a stream
            bis = new Base64.InputStream(
                      new java.io.BufferedInputStream(
                      new java.io.FileInputStream( file ) ), Base64.ENCODE );

            // Read until done
            while( ( numBytes = bis.read( buffer, length, 4096 ) ) >= 0 )
                length += numBytes;

            // Save in a variable to return
            encodedData = new String( buffer, 0, length, Base64.PREFERRED_ENCODING );

        }   // end try
        catch( java.io.IOException e )
        {
            logger.error( Logger.SECURITY_FAILURE, "Error encoding from file " + filename, e );
        }   // end catch: IOException
        finally
        {
            try{ bis.close(); } catch( Exception e) {}
        }   // end finally

        return encodedData;
        }   // end encodeFromFile

    /**
     * Reads <tt>infile</tt> and encodes it to <tt>outfile</tt>.
     *
     * @param infile Input file
     * @param outfile Output file
     * @return true if the operation is successful
     * @since 2.2
     */
    public static boolean encodeFileToFile( String infile, String outfile )
    {
        boolean success = false;
        java.io.InputStream in = null;
        java.io.OutputStream out = null;
        try{
            in  = new Base64.InputStream(
                      new java.io.BufferedInputStream(
                        new java.io.FileInputStream( infile ) ),
                      Base64.ENCODE );
            out = new java.io.BufferedOutputStream( new java.io.FileOutputStream( outfile ) );
            byte[] buffer = new byte[65536]; // 64K
            int read = -1;
            while( ( read = in.read(buffer) ) >= 0 ){
                out.write( buffer,0,read );
            }   // end while: through file
            success = true;
        } catch( java.io.IOException exc ){
            logger.error( Logger.SECURITY_FAILURE, "Problem encoding file to file", exc );
        } finally{
            try{ in.close();  } catch( Exception exc ){}
            try{ out.close(); } catch( Exception exc ){}
        }   // end finally

        return success;
    }   // end encodeFileToFile

    /**
     * Reads <tt>infile</tt> and decodes it to <tt>outfile</tt>.
     *
     * @param infile Input file
     * @param outfile Output file
     * @return true if the operation is successful
     * @since 2.2
     */
    public static boolean decodeFileToFile( String infile, String outfile )
    {
        boolean success = false;
        java.io.InputStream in = null;
        java.io.OutputStream out = null;
        try{
            in  = new Base64.InputStream(
                      new java.io.BufferedInputStream(
                      new java.io.FileInputStream( infile ) ),
                      Base64.DECODE );
            out = new java.io.BufferedOutputStream( new java.io.FileOutputStream( outfile ) );
            byte[] buffer = new byte[65536]; // 64K
            int read = -1;
            while( ( read = in.read(buffer) ) >= 0 ){
                out.write( buffer,0,read );
            }   // end while: through file
            success = true;
        } catch( java.io.IOException exc ){
            logger.error( Logger.SECURITY_FAILURE, "Problem decoding file to file", exc );
        } finally{
            try{ in.close();  } catch( Exception exc ){}
            try{ out.close(); } catch( Exception exc ){}
        }   // end finally

        return success;
    }   // end decodeFileToFile

    /* ********  I N N E R   C L A S S   I N P U T S T R E A M  ******** */

    /**
     * A {@link Base64.InputStream} will read data from another
     * <tt>java.io.InputStream</tt>, given in the constructor,
     * and encode/decode to/from Base64 notation on the fly.
     *
     * @see Base64
     * @since 1.3
     */
    public static class InputStream extends java.io.FilterInputStream
    {
        private boolean encode;         // Encoding or decoding
        private int     position;       // Current position in the buffer
        private byte[]  buffer;         // Small buffer holding converted data
        private int     bufferLength;   // Length of buffer (3 or 4)
        private int     numSigBytes;    // Number of meaningful bytes in the buffer
        private int     lineLength;
        private boolean breakLines;     // Break lines at less than 80 characters
        private int     options;        // Record options used to create the stream.
        private byte[]  decodabet;      // Local copies to avoid extra method calls

        /**
         * Constructs a {@link Base64.InputStream} in DECODE mode.
         *
         * @param in the <tt>java.io.InputStream</tt> from which to read data.
         * @since 1.3
         */
        public InputStream( java.io.InputStream in )
        {
            this( in, DECODE );
        }   // end constructor

        /**
         * Constructs a {@link Base64.InputStream} in
         * either ENCODE or DECODE mode.
         * <p>
         * Valid options:<pre>
         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DONT_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)
         *     <i>Note: Technically, this makes your encoding non-compliant.</i>
         * </pre>
         * <p>
         * Example: <code>new Base64.InputStream( in, Base64.DECODE )</code>
         *
         *
         * @param in the <tt>java.io.InputStream</tt> from which to read data.
         * @param options Specified options
         * @see Base64#ENCODE
         * @see Base64#DECODE
         * @see Base64#DONT_BREAK_LINES
         * @since 2.0
         */
        public InputStream( java.io.InputStream in, int options )
        {
            super( in );
            this.breakLines   = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES;
            this.encode       = (options & ENCODE) == ENCODE;
            this.bufferLength = encode ? 4 : 3;
            this.buffer       = new byte[ bufferLength ];
            this.position     = -1;
            this.lineLength   = 0;
            this.options      = options; // Record for later, mostly to determine which alphabet to use
            this.decodabet    = getDecodabet(options);
        }   // end constructor

        /**
         * Reads enough of the input stream to convert
         * to/from Base64 and returns the next byte.
         *
         * @return next byte
         * @throws java.io.IOException
         * @since 1.3
         */
        public int read() throws java.io.IOException
        {
            // Do we need to get data?
            if( position < 0 )
            {
                if( encode )
                {
                    byte[] b3 = new byte[3];
                    int numBinaryBytes = 0;
                    for( int i = 0; i < 3; i++ )
                    {
                        try
                        {
                            int b = in.read();

                            // If end of stream, b is -1.
                            if( b >= 0 )
                            {
                                b3[i] = (byte)b;
                                numBinaryBytes++;
                            }   // end if: not end of stream

                        }   // end try: read
                        catch( java.io.IOException e )
                        {
                            // Only a problem if we got no data at all.
                            if( i == 0 )
                                throw e;

                        }   // end catch
                    }   // end for: each needed input byte

                    if( numBinaryBytes > 0 )
                    {
                        encode3to4( b3, 0, numBinaryBytes, buffer, 0, options );
                        position = 0;
                        numSigBytes = 4;
                    }   // end if: got data
                    else
                    {
                        return -1;
                    }   // end else
                }   // end if: encoding

                // Else decoding
                else
                {
                    byte[] b4 = new byte[4];
                    int i = 0;
                    for( i = 0; i < 4; i++ )
                    {
                        // Read four "meaningful" bytes:
                        int b = 0;
                        do{ b = in.read(); }
                        while( b >= 0 && decodabet[ b & 0x7f ] <= WHITE_SPACE_ENC );

                        if( b < 0 )
                            break; // Reads a -1 if end of stream

                        b4[i] = (byte)b;
                    }   // end for: each needed input byte

                    if( i == 4 )
                    {
                        numSigBytes = decode4to3( b4, 0, buffer, 0, options );
                        position = 0;
                    }   // end if: got four characters
                    else if( i == 0 ){
                        return -1;
                    }   // end else if: also padded correctly
                    else
                    {
                        // Must have broken out from above.
                        throw new java.io.IOException( "Improperly padded Base64 input." );
                    }   // end

                }   // end else: decode
            }   // end else: get data

            // Got data?
            if( position >= 0 )
            {
                // End of relevant data?
                if( /*!encode &&*/ position >= numSigBytes )
                    return -1;

                if( encode && breakLines && lineLength >= MAX_LINE_LENGTH )
                {
                    lineLength = 0;
                    return '\n';
                }   // end if
                else
                {
                    lineLength++;   // This isn't important when decoding
                                    // but throwing an extra "if" seems
                                    // just as wasteful.

                    int b = buffer[ position++ ];

                    if( position >= bufferLength )
                        position = -1;

                    return b & 0xFF; // This is how you "cast" a byte that's
                                     // intended to be unsigned.
                }   // end else
            }   // end if: position >= 0

            // Else error
            else
            {
                // When JDK1.4 is more accepted, use an assertion here.
                throw new java.io.IOException( "Error in Base64 code reading stream." );
            }   // end else
        }   // end read

        /**
         * Calls {@link #read()} repeatedly until the end of stream
         * is reached or <var>len</var> bytes are read.
         * Returns number of bytes read into array or -1 if
         * end of stream is encountered.
         *
         * @param dest array to hold values
         * @param off offset for array
         * @param len max number of bytes to read into array
         * @return bytes read into array or -1 if end of stream is encountered.
         * @throws java.io.IOException
         * @since 1.3
         */
        public int read( byte[] dest, int off, int len ) throws java.io.IOException
        {
            int i;
            int b;
            for( i = 0; i < len; i++ )
            {
                b = read();

                //if( b < 0 && i == 0 )
                //    return -1;

                if( b >= 0 )
                    dest[off + i] = (byte)b;
                else if( i == 0 )
                    return -1;
                else
                    break; // Out of 'for' loop
            }   // end for: each byte read
            return i;
        }   // end read

    }   // end inner class InputStream


    /* ********  I N N E R   C L A S S   O U T P U T S T R E A M  ******** */

    /**
     * A {@link Base64.OutputStream} will write data to another
     * <tt>java.io.OutputStream</tt>, given in the constructor,
     * and encode/decode to/from Base64 notation on the fly.
     *
     * @see Base64
     * @since 1.3
     */
    public static class OutputStream extends java.io.FilterOutputStream
    {
        private boolean encode;
        private int     position;
        private byte[]  buffer;
        private int     bufferLength;
        private int     lineLength;
        private boolean breakLines;
        private byte[]  b4; // Scratch used in a few places
        private boolean suspendEncoding;
        private int options; // Record for later
        private byte[]  decodabet;      // Local copies to avoid extra method calls

        /**
         * Constructs a {@link Base64.OutputStream} in ENCODE mode.
         *
         * @param out the <tt>java.io.OutputStream</tt> to which data will be written.
         * @since 1.3
         */
        public OutputStream( java.io.OutputStream out )
        {
            this( out, ENCODE );
        }   // end constructor

        /**
         * Constructs a {@link Base64.OutputStream} in
         * either ENCODE or DECODE mode.
         * <p>
         * Valid options:<pre>
         *   ENCODE or DECODE: Encode or Decode as data is read.
         *   DONT_BREAK_LINES: don't break lines at 76 characters
         *     (only meaningful when encoding)
         *     <i>Note: Technically, this makes your encoding non-compliant.</i>
         * </pre>
         * <p>
         * Example: <code>new Base64.OutputStream( out, Base64.ENCODE )</code>
         *
         * @param out the <tt>java.io.OutputStream</tt> to which data will be written.
         * @param options Specified options.
         * @see Base64#ENCODE
         * @see Base64#DECODE
         * @see Base64#DONT_BREAK_LINES
         * @since 1.3
         */
        public OutputStream( java.io.OutputStream out, int options )
        {
            super( out );
            this.breakLines   = (options & DONT_BREAK_LINES) != DONT_BREAK_LINES;
            this.encode       = (options & ENCODE) == ENCODE;
            this.bufferLength = encode ? 3 : 4;
            this.buffer       = new byte[ bufferLength ];
            this.position     = 0;
            this.lineLength   = 0;
            this.suspendEncoding = false;
            this.b4           = new byte[4];
            this.options      = options;
            this.decodabet    = getDecodabet(options);
        }   // end constructor

        /**
         * Writes the byte to the output stream after
         * converting to/from Base64 notation.
         * When encoding, bytes are buffered three
         * at a time before the output stream actually
         * gets a write() call.
         * When decoding, bytes are buffered four
         * at a time.
         *
         * @param theByte the byte to write
         * @throws java.io.IOException
         * @since 1.3
         */
        public void write(int theByte) throws java.io.IOException
        {
            // Encoding suspended?
            if( suspendEncoding )
            {
                super.out.write( theByte );
                return;
            }   // end if: supsended

            // Encode?
            if( encode )
            {
                buffer[ position++ ] = (byte)theByte;
                if( position >= bufferLength )  // Enough to encode.
                {
                    out.write( encode3to4( b4, buffer, bufferLength, options ) );

                    lineLength += 4;
                    if( breakLines && lineLength >= MAX_LINE_LENGTH )
                    {
                        out.write( NEW_LINE );
                        lineLength = 0;
                    }   // end if: end of line

                    position = 0;
                }   // end if: enough to output
            }   // end if: encoding

            // Else, Decoding
            else
            {
                // Meaningful Base64 character?
                if( decodabet[ theByte & 0x7f ] > WHITE_SPACE_ENC )
                {
                    buffer[ position++ ] = (byte)theByte;
                    if( position >= bufferLength )  // Enough to output.
                    {
                        int len = Base64.decode4to3( buffer, 0, b4, 0, options );
                        out.write( b4, 0, len );
                        //out.write( Base64.decode4to3( buffer ) );
                        position = 0;
                    }   // end if: enough to output
                }   // end if: meaningful base64 character
                else if( decodabet[ theByte & 0x7f ] != WHITE_SPACE_ENC )
                {
                    throw new java.io.IOException( "Invalid character in Base64 data." );
                }   // end else: not white space either
            }   // end else: decoding
        }   // end write

        /**
         * Calls {@link #write(int)} repeatedly until <var>len</var>
         * bytes are written.
         *
         * @param theBytes array from which to read bytes
         * @param off offset for array
         * @param len max number of bytes to read into array
         * @throws java.io.IOException
         * @since 1.3
         */
        public void write( byte[] theBytes, int off, int len ) throws java.io.IOException
        {
            // Encoding suspended?
            if( suspendEncoding )
            {
                super.out.write( theBytes, off, len );
                return;
            }   // end if: supsended

            for( int i = 0; i < len; i++ )
            {
                write( theBytes[ off + i ] );
            }   // end for: each byte written

        }   // end write

        /**
         * Method added by PHIL. [Thanks, PHIL. -Rob]
         * This pads the buffer without closing the stream.
         * @throws java.io.IOException
         */
        public void flushBase64() throws java.io.IOException
        {
            if( position > 0 )
            {
                if( encode )
                {
                    out.write( encode3to4( b4, buffer, position, options ) );
                    position = 0;
                }   // end if: encoding
                else
                {
                    throw new java.io.IOException( "Base64 input not properly padded." );
                }   // end else: decoding
            }   // end if: buffer partially full

        }   // end flush

        /**
         * Flushes and closes (I think, in the superclass) the stream.
         *
         * @throws java.io.IOException
         * @since 1.3
         */
        public void close() throws java.io.IOException
        {
            // 1. Ensure that pending characters are written
            flushBase64();

            // 2. Actually close the stream
            // Base class both flushes and closes.
            super.close();

            buffer = null;
            out    = null;
        }   // end close

        /**
         * Suspends encoding of the stream.
         * May be helpful if you need to embed a piece of
         * base640-encoded data in a stream.
         *
         * @throws java.io.IOException
         * @since 1.5.1
         */
        public void suspendEncoding() throws java.io.IOException
        {
            flushBase64();
            this.suspendEncoding = true;
        }   // end suspendEncoding

        /**
         * Resumes encoding of the stream.
         * May be helpful if you need to embed a piece of
         * base640-encoded data in a stream.
         *
         * @since 1.5.1
         */
        public void resumeEncoding()
        {
            this.suspendEncoding = false;
        }   // end resumeEncoding

    }   // end inner class OutputStream

}   // end class Base64
